The phrase "are considered complex and" is correct and usable in written English.
It can be used when discussing subjects or topics that are perceived as intricate or difficult to understand, often in academic or analytical contexts.
Example: "The theories of quantum mechanics are considered complex and require a deep understanding of advanced mathematics."
Alternatives: "are viewed as intricate and" or "are regarded as complicated and".
Because the intervention includes several components it could be considered complex and difficult to evaluate exactly what was the main influence of the participants' experiences [ 23].
While the management of cardiovascular disease is considered complex and too large a task to address with CM, alternative medicine practitioners provide patients with the individualized attention and care that is required to assist them with their health concerns [ 47].
One the one hand, cities are considered complex systems and all the components are not working independently but interacting with each other.
However, relationships between invertebrates and plant detritus are considered complex due to the physical and chemical alterations that occur during the decomposition of organic matter (Gonçalves et al. 2004).
Most respiratory diseases are considered complex diseases as their susceptibility and outcomes are determined by the interaction between host-dependent factors (genetic factors, comorbidities, etc).
For the purposes of this analysis, mutations within 10 bp were considered "complex mutations" and treated as a single event, thus not constituting clusters unto themselves.
Of these 17 methods, five were considered "complex," nine were "intermediate," and three were "simple," based on the number of characteristics examined.
These items are using quantitative measurements, so the current assessing way is considered complex besides the consumption of time and effort without reaching significantly accurate results.
Such systems are typically considered complex and they are modelled using abstractions.
Community-based health promotion (CBHP) interventions are usually considered complex and difficult to plan, perform, and evaluate.
